Executing the script on a blank form in FF would give the correct response, Enter in a name. In IE, I would get an error on Line 15 about Object Expected (in the script, line 15 is actually a commented out line, so that error isn’t very helpful).

I then remembered something about IE automatically creating variables from a form by the name/id of the form field on the page. Since my variable name, and field name were the same, it would try to compare its self created object against my test, instead of the variable that I was assigning, thus creating an error.

To work around this, I had to rename all of my variables (I could have also renamed all of my fields):